The present invention relates generally to a rectangular paperboard package which is formed from a single sheet of paperboard material and, in particular, to a package which is capable of holding a liquid product and is provided with an easy open, tear away top portion. The present invention also concerns a unique blank structure for constructing the paperboard package.
Paperboard materials are becoming increasingly popular as a packaging material, especially in the food industry. A sheet of paperboard material typically includes a central structural layer of paper to provide strength and rigidity to the associated package. In some instances, a layer of aluminum foil can be adhered to one surface of the paperboard to serve as a barrier layer against the passage of contaminates into the package. Generally, both surfaces of the paperboard/foil combination are then coated with a heat sealable thermoplastic material. While a number of specific constructions are known, it is generally accepted practice to fold a precut and prescored sheet of paperboard material into a predetermined package configuration, and to seal the packages by applying heat and pressure to certain contacting surfaces of the paperboard.
Many types of paperboard packages capable of holding a liquid and provided with some type of opening means have been proposed. Examples of such packages are disclosed in U.S. Pat. Nos. 3,347,444; 4,317,518; 4,520,929; and 4,546,884. While the packages disclosed in these patents have been found to be satisfactory for certain packaging applications, there has been a need in the industry for a rectangular paperboard package which is capable of holding liquid and which can be produced on an economical basis.